Beans need to be heat treated. Essentially all legumes and pulses do. Maybe that was done if they are dried, maybe it wasn't. Fresh beans shouldn't be fed at all. The heat treatment breaks down certain anti-nutritive properties.
Whole Grain feeds are all the rage with some (I am not among them). On the positives, being whole, they don't spoil nearly as quickly as processed feed. On the negative, birds tend to select favorites based on dominance in the flock pecking order, which usually results in very expensive feed producing nutritionally poorly fed birds, even if the mix itself is well designed. BYC has dozens, if not hundreds, of related posts. Homemade mixes from youtube videos and websites with those ingredients almost always have too much fat, and almost always are deficient in one or more amino acids, as well as several vitamins.
Assuming you are using a whole grain commercial feed, most of those problems are largely mitigated by serving as a sprouted or fermented feed - meaning soak them in water for a few days before serving (basically). and the fine powder at the bottom of the bag is likely the vitamin mix added to make a whole grain feed into a complete diet.
